GEISHA: an in situ hybridization gene expression resource for the chicken embryo.

An important and ongoing focus of biomedical and agricultural avian research is to understand gene function, which for a significant fraction of genes remains unknown. A first step is to determine when and where genes are expressed during development and in the adult. Whole mount in situ hybridization gives precise spatial and temporal resolution of gene expression throughout an embryo, and a comprehensive analysis and centralized repository of in situ hybridization information would provide a valuable research tool. The GEISHA project (gallus expression in situ hybridization analysis) was initiated to explore the utility of using high-throughput in situ hybridization as a means for gene discovery and annotation in chicken embryos, and to provide a unified repository for in situ hybridization information. This report describes the design and implementation of a new GEISHA database and user interface (www.geisha.arizona.edu), and illustrates its utility for researchers in the biomedical and poultry science communities. Results obtained from a high throughput screen of microRNA expression in chicken embryos are also presented. Copyright 2007 S. Karger AG, Basel.